The present invention relates in general to tumbler wheel lock mechanisms suitable for changeable key operated locks and dial operated combination locks, and more particularly in one example to changeable key locks of the type having a plurality of peripherally gated tumbler wheels with changeable hub portions adapted to be conditioned upon manipulation of a key inserted therein to assume positions appropriate to the salients or wards of the particular key therein for setting the lock to the key configuration.
Conventional key locks usually employ pivoted lever tumblers or axially slidable pin tumblers to engage the contoured edge of the key blade and adjust the lever tumblers or pin tumblers to positions releasing the lock to a condition so that the bolt can be retracted. These key operated locks are usually of an entirely different construction and operate in accordance with different principles from conventional locks of the class known as combination locks. Combination locks usually comprise three or more tumbler wheels which are loosely journalled in coaxial, side-by-side spaced relation for rotation within a lock casing on a tubular arbor or tumbler post projecting inwardly from the front wall of the casing. The lock dial, which usually has one hundred peripheral calibration marks thereon, is affixed to a dial spindle which extends through the bore of the tumbler post and has keyed to the inner end thereof a disc-like drive cam which is likewise arranged coaxially with and spaced rearwardly from the tumbler wheels. A drive pin projects forwardly from the drive cam and has a lost motion connection through a conventional fly with the rearmost tumbler wheel to drive the tumbler wheel in selected relation to the drive cam. A similar lost motion connection is provided between each of the successive tumbler wheels so that each of the tumbler wheels may be driven upon predetermined rotation of the drive cam to position the peripheral notch or gate in each of the tumbler wheels in alignment to receive a fence projecting laterally from a fence lever in overlying relation with the tumbler wheel peripheries. The position of the fence in relation to the length of the fence lever nose is usually such that the fence is slightly spaced from the peripheries of the tumblers when the fence lever nose rides on the periphery of the drive cam.
An object of the present invention is the provision of a novel lock construction for key operated locks, particularly for use with keys of the European type having wards or salients projecting from diametrically opposite portions of the shaft or stem of the key, wherein the locking mechanism includes a plurality of peripherally gated tumbler wheels similar to the type employed in combination locks, coactive with a fence lever pivotally coupled to a sliding bolt and a fence lever controlling cam movable by the key when inserted into the lock casing, whereby the key can adjust the tumbler wheels to release the fence lever to a position coupling it with the cam for retracting the bolt to an unlocking position.
Another object of the present invention is the provision of a key lock construction of the type described in the immediately preceding paragraph, wherein the tumbler wheels are provided with hubs which are releasably coupled with the peripheral portions of the tumbler wheels and which are apertured and shouldered to receive the salient or ward portions of the key therein to be angularly adjusted thereby for disposing the tumbler wheels in position to release the lock to unlocking condition.
Another object of the present invention is the provision of a lock construction of the type described in the two immediately preceding paragraphs, wherein the positions of the hub portions of the tumbler wheels may be changed responsive to adjustment of a different key disposed therein from the one to which they were previously set, when the hubs are decoupled from the peripheral portions of the tumbler wheels, to adjust the tumbler wheel hubs to the salient or ward configuration of a different key.
Another object of the present invention is the provision of a key operated, rotatable tumbler wheel type lock of the type described in the preceding paragraphs, wherein the fence lever is normally releasably held in a position spacing the fence lever and fence out of contact with the associated cam and tumbler wheel peripheries and wherein spring means are periodically activated by adjustment of the cam responsive to movement of the key to store up energy in the spring means and then release the same suddenly to impel the fence lever to an unlocking position if the tumbler wheels are properly adjusted to release the lock.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.